NORMAN SELFE. LXV. 



When, a few months since, at the expiration of an old lease, 

 the wharf reverted to its owner, Mr. Chas. Parbury, it was 

 understood that the lease was not renewed, owing to the sup- 

 posed impossibility of building a jetty over such deep water and 

 soft mud. Mr. Parbury thus found himself in possession of an 

 isolated broadside wharf, with a water frontage of only 280 feet. 

 o£ no use whatever in connection with modern ships ; he, 

 therefore, with a view to modernise and utilise his property 

 to its fullest extent, consulted the author, who formulated 

 the scheme of improvements which have just been completed. 

 These include a forty-ton sextuple-power waggon hoist, with a 

 platform thirty feet long, and the jetty which is the subject of 

 this paper. 



The dimensions of the jetty ultimately settled upon, and as 

 built, are 350 ft. long and 60 ft. beam — as shown by the 

 accompanying plan. When the position had been determined 

 upon, two lines of soundings and borings were made, which 

 showed that the rock was reached through about 50 ft. of mud 

 or silt, and clay — approximately, about half of each. The upper 

 25 feet of silt is so soft as to be practically of no use as a support 

 to the piles ; but the clay is extremely tenacious, generally, when 

 down fifteen or twenty feet into it. The rock bottom was 

 found to be irregular, and falling to the north side ; in some cases 

 there was as much as nine feet difference in the width of the 

 jetty. 



The borings, when plotted as per plan exhibited, made two 

 things very clear, viz., that the rock, through a great part of its 

 length, was more than 120 ft. below the deck of the jetty, and 

 that diagonal piles would have to be 140 ft. long. It was also 

 seen that until the clay was reached, there was no support, either 

 vertically or laterally for the piles. Sufficient vertical support 

 could, perhaps, have been obtained by " collaring " the piles at 

 the heavy clay line, but considerations of lateral stability deter- 

 mined that all the piles should go to the rock. 



The specification stipulated that the piles at the toe might 

 vary between 13 to 15 in. inside the bark, 14 in. being the 



